The aim of the present project is to compare, and study the relationship, between the left hemisphere specialization in verbal material and the right hemisphere specialization in nonverbal material. Comparable dichotic presentations of digit and tone sequences will be administered to the same group of right-handed subjects, including in one condition simultaneous presentation of digits to the right ear and tones to the left ear, and performance will be measured with both the recall and recognition procedures. Some of the questions asked are: 1) At what stage of information processing does hemispheric specialization become evident? 2) Is hemispheric specialization more pronounced for verbal than for nonverbal material, or vice versa? 3) To what extent are the respective specializations of the two hemispheres correlated? 4) Is the common practice of using recall procedure for verbal material and recognition procedure for musical material indeed optimal? 5) Which hemisphere will be dominant when simultaneously each one is presented with a task of its own specialty? Procedural improvements and detailed data analysis are incorporated also with the aim to obtain more sensitive ear difference indices, such that the dichotic input paradigm might be used as a reliable clinical tool for assessing functional lateralization for individual cases, and as an aid for localizing brain damage and monitoring functional recovery in selected cases.